1. Field of the Invention
The present invention relates to an Internet telephone system for making a long-distance call at a low charge by using the Internet.
2. Description of the Related Art
A voice communication system using the wide-area data communication network of the Internet, known as the Internet telephone system, is disclosed, for example, in Japanese Laid-open Patent H11-225218.
In the Internet telephone system disclosed in Japanese Laid-open Patent H11-225218, when it is ready to make an Internet call, it is notified between ISDN terminal adapters (TA), by an exchange of sub-addresses or a user-user information notice, and the calling side and destination side ISDN TA automatically dial up to the Internet, and an Internet call is started.
FIG. 16 is a configuration showing the conventional Internet telephone system disclosed in the publication. FIG. 17 is a sequence diagram showing the operation of the conventional Internet telephone system.
The conventional Internet telephone system shown in FIG. 16 and FIG. 17 makes an Internet call in the following procedure.
(1) The destination side ISDN TA 105 receives a call setting 104 including a sub-address of a predetermined number from the calling side ISDN TA 102.
(2) The TA 105, receiving the call setting 104, rings the bell of a destination side telephone set 106 connected to itself.
(3) The TA 105 detects when the user hooks up the telephone set 106, and connects to a destination side access point 109.
(4) After connection, the TA 105 puts the predetermined number and acquired IP address on the sub-address of a call setting 107, and sends out to the calling side ISDN TA 102.
(5) The TA 102 receives the predetermined number and the IP address acquired at the destination side as the sub-address of the call setting 107, and connects to a calling side access point 108.
(6) After connection, the TA 102 sends the calling side IP address to the destination side IP address, and the both sides starts an Internet call.
(7) After start of the Internet call, the TA 102 and 105 send out a cut-off signal to the call setting sent from each side in order to terminate the mutual call settings, and layer 3 message for telephone call on the ISDN is closed.
The conventional Internet telephone system involves the following problems.
(1) The ISDN communication charge and the Internet connection charge at the destination side are at a charge of the destination party, and it is hard to obtain understanding.
(2) Call is possible only to the telephone set connected to the ISDN TA.
It is hence an object of the invention to present an Internet telephone system allowing the destination side telephone set to be free from ISDN communication charge and Internet connection charge, and allowing to make a call to a telephone set not connected to an ISDN terminal adapter (TA).
To solve the problems, the Internet telephone system of the invention comprises a calling side telephone set, a calling side ISDN TA connected to the calling side telephone set, a destination side ISDN TA for receiving a notice of a user-user information notice or a call setting from the calling side ISDN TA, and a destination side telephone set connected to the destination side ISDN TA, and makes an Internet call in the following procedure.
The calling side ISDN TA:
(1) judges if the destination is accessible to an Internet call or not when the telephone number of the destination side telephone set is specified by the calling side telephone set, and
(2) if judging that an Internet call is possible, sets the predetermined number, Internet connection member identification number and password, on the user-user information notice or the sub-address of the call setting, and sends out to the destination side ISDN TA.
The destination side ISDN TA:
(1) rings the bell of the destination side telephone set when receiving the predetermined number set on the user-user information notice or the sub-address of the call setting,
(2) connects to the access point of the destination side provider by the transmitted Internet connection member identification number and password when the destination side telephone set is hooked up, and
(3) transmits the destination side IP address acquired at the destination side access point to the calling side ISDN TA by putting the destination side IP address on the sub-address of the call setting or by user-user information notice.
The calling side ISDN TA:
(1) receives the destination side IP address, and connects to the access point of the calling side provider, and
(2) makes an Internet call by transmitting the calling side IP address acquired at the calling side access point to the destination side on the Internet.
The destination side telephone set utilizes the Internet connection member identification number and password sent from the calling side telephone set.
Further, the Internet telephone system of the invention comprises a calling side telephone set, a calling side ISDN TA connected to the calling side telephone set, a destination side ISDN TA for receiving a call setting from the calling side ISDN TA, and a destination side telephone set connected to the destination side ISDN TA, in which the destination side ISDN terminal adapter makes a call to the exchange network in the own local region when receiving a call setting of Internet call from the calling side ISDN TA.